1. Field of the Invention
The present invention relates to a structure of a touch screen which is integrally implemented with a liquid crystal panel.
2. Description of the Related Arts
A touch screen panel is an input unit which is able to input a user's instruction by selecting an instruction content displayed in a screen of an image display unit using the human hand or an object.
For this, the touch screen panel is installed on a front surface of the image display unit to thereby convert a touch position touched directly to the human hand or the object to an electric signal. Accordingly, the instruction content selected from the touch position is received as an input signal.
Such a touch screen panel may replace a separate input unit which is operably connected to the image display unit like a keyboard and a mouse, and thus the use range thereof has been gradually increasing.
However, when the touch screen panel is attached to an upper part of a panel of the image display unit, a whole volume of the image display unit increases, so a problem such as the degradation in convenience to carry out may occur. Accordingly, the development of a thin touch screen panel has been recently required.
However, in the case of a general touch screen panel, to improve apparatus strength, a window is additionally installed on an upper surface of the touch screen panel. Thus, this is disadvantageous that the touch screen panel increases in thickness, thereby going counter to the trend toward a thinner touch screen panel. Furthermore, the window may be generally implemented as a strengthened glass substrate, but to use the strengthened glass substrate as the window, after cutting the glass substrate into cell units, a process for strengthening individually the cell units should be carried out. The production of the touch screen panel using the window of each cell unit is disadvantageous that mass production cannot be secured.
That is, like a structure illustrated in FIG. 1, in a conventional touch screen panel having an integrated liquid crystal panel, a touch screen panel TSP bonded onto an upper part of the liquid crystal panel L is disposed, and the touch screen panel is implemented in a sequential stacked structure comprising an OCA (Optical Clear Adhesive) 1, a first electrode layer 2, another OCA 3, a second electrode layer 4, and still another OCA 5 on an upper substrate which implements a TFT (thin film transistor) of the liquid crystal panel L. As aforesaid, it is general to secure the strength of a whole product by using six side strengthened glass for a cover lens as a construction material of a window 6. However, as aforesaid, for the six side strengthened glass, after cutting the glass substrate into the cell units, a process for strengthening individually the cut cell units should be performed. That is, a process for strengthening a total of six unit surfaces should be implemented, and thus the problem in that mass production is very decreased is generated.
On the other hand, when the touch screen panel is manufactured in a ledger state using a non-strengthened glass substrate as the window, fracture strength of the window is weak, so the problem that a function as a window cannot be performed is generated.